ENERGY INDICATORS OF ELECTRIC DRIVE OF CRANE LIFTING MECHANISMS
The operational quality of the work of crane mechanisms, their performance, as well as the problem of energy conservation largely depends on the electric drive. Industrial electric drive consumes 60- 70% of all electric power produced according to various estimates. In connection with the increase in electricity prices and the limited capacity to increase the power generating units, the problem of reducing electricity consumption is an urgent task. The purpose of the work is to compare electricity losses during the operation of an asynchronous electric drive with a voltage converter and with a frequency converter with and without recovery of electric energy. In order to achieve this goal, an analysis of electricity consumption during the operation of various electric drives was carried out. With the help of the automated system, the calculation of electricity consumption was performed using different electric drives for crane lifting mechanisms. The automated system of comparison of technical and economic efficiency of asynchronous electric drives of crane mechanisms allows to promptly conclude that it is expedient to use an optimal electric drive in the specific conditions of operation of a crane mechanism. Due to the unification of approaches to the analysis of operating modes of lifting mechanisms, the program calculates the losses of electricity in static and dynamic modes. The program calculates the potential energy savings and payback period of the electric drive, taking into account the load, moments of inertia and relative time with reduced speeds. Considering separate alternative electric drives of lifting mechanisms came to the conclusion. Electricity consumption by asynchronous motors of crane mechanisms depends not only on the type of electric drive, but also on the features of the technological process and modes of their operation. With an increase in the power of the electric motor there is a relatively less power saving in the transition to more complex electric drives. The electric drive with a voltage converter consumes more electricity in all modes compared to rheostatic regulation. It is shown that at low speeds with reduced speeds, an electric drive with a frequency converter without a recuperator consumes more electricity than an electric drive with a rheostatic control.